ULV 



429 



UNO 



Ulva, n., ulv'-a (L. ulva, sedge), a 

 genus of Algae, distinguished by 

 their green colour : Ulva latis- 

 sima, lat-is'-sim-a (L. Idtissimus, 

 broadest from Idtus, broad), 

 a familiar species, frequently 

 attached to oysters, and called 

 oyster-green : U. lactuca, Idk- 

 tuk'-a (L. lactuca, lettuce), a 

 species eaten under the name 

 Green Laver. 



umbel, n., umf-bel (L. umbella, a 

 sun-shade, aparasol from umbra, 

 a shadow), in bot., a particular 

 arrangement of the flowers of 

 certain plants, in which the 

 peduncles, springing from a com- 

 mon centre, rise till they form 

 a flat tuft, as in the familiar 

 example of the inflorescence of 

 the carrot, or hemlock. NOTE. 

 In the corymb, the flowers form 

 a flat head, but they do not, as 

 in the umbel, spring from a 

 common centre, umbellate, a., 

 Hmf'bel-ldt, in bot., having the 

 flowers arranged in a round, flat 

 head, with the peduncles spring- 

 ing from a common centre ; in 

 zool. , having a number of nearly 

 equal radii, all proceeding from a 

 common centre. 



Umbelliferse, n. plu. , um'-beUf-er-e 

 (L. umbella, a sun-shade, a para- 

 sol ; fero, I bear), the Umbellif- 

 erous family, an Order of plants, 

 having various properties, some 

 used as articles of diet, some 

 yield gum, resinous, and other 

 substances, and some are highly 

 poisonous ; the Apiacese of Lind- 

 ley : umbelliferous, a. , um'bel- 

 lif-er-us, producing or bearing 

 umbels : umbellule, n., umf-bel- 

 ul, a small umbel, seen in the 

 compound umbellate flowers of 

 many Umbelliferse. 



umbilicus, n., um'-bil-ik'-us (L. 

 umbilicus, the navel), the central 

 spot of the abdomen, marked by 

 a depression ; the navel ; in bot., 

 the scar by which a seed is 

 attached to the placenta, more 



usually called the hilum; in 200?., 

 the aperture at the base of the 

 axis of certain univalve shells, 

 when so seen they are said to be 

 umbilicated or perforated : um- 

 bilical, a., tim'-Ul-lWal, of or 

 pert, to the navel: umbilical cord, 

 in anat., a cord-like substance 

 which extends from the placenta 

 to the navel of the foetus ; the 

 extremity of the malleus towards 

 which the fibres of the membrana 

 tympani converge ; in bot., the 

 prolongation by which the ovule 

 is attached to the placenta : 

 umbilicate, a., um-bil'-ik-at, in 

 bot., having a central depres- 

 sion ; fixed to a stalk by a point 

 in the centre : also umbilicated, 

 a., -dt-'ed, in same sense. 



umbo, n., um<bo (L. umbo, the 

 boss of a shield), in bot., a pro- 

 tuberant part or elevation on a 

 surface, like the boss of an ancient 

 shield ; in zool. , the beak of a 

 bivalve shell : umbonate, a., 

 umf-bdU'dt, having a knob in the 

 centre; having a central elevation 

 like the boss of an anc. shield. 



umbraculiferous, a., um-brak'-ul- 

 if'er'us (L. umbrdculum, a sun- 

 shade, an umbrella from umbra, 

 a shade ; fero, I bear), in bot., 

 having the form of an expanded 

 umbrella : umbraculiform, a., 

 um'-brak-ul'-iform (L. forma, 

 shape), in same sense as preceding: 

 umbraculum, n.,ft,m-brdk'ul-um, 

 in bot., the cap borne on the seta 

 of Marchantia, Ord. Hepaticse. 



umbrella, n., um-brel'-la (It. om- 

 brella, L. umbella, an umbrella 

 from L. umbra, a shade), in zool, 

 the contractile disc of one of the 

 Lucernarida. 



uncinate, a., un'-sin-dt (L. uncin- 

 us, a hook, a barb), in bot., 

 provided with a hooked process ; 

 ir zool., furnished with hooks or 

 bent spines ; in anat. , a process 

 of the ethmoid bone : unciform, 

 a. , tin'-sfrform (L. forma, shape), 

 having a curved or hooked form ; 



